- Email: [email protected]
Benign temporomandibular joint tumours with extension to infratemporal fossa and skull base: condyle preserving approach
YIJOM-4343; No of Pages 7
Int. J. Oral Maxillofac. Surg. 2019; xxx: xxx–xxx https://doi.org/10.1016/j.ijom.2019.12.009, available online at https://www.sciencedirect.com
Clinical Paper Clinical Pathology
Benign temporomandibular joint tumours with extension to infratemporal fossa and skull base: condyle preserving approach
X. Liu1, S. Wan1, A. Abdelrehem2, M. Chen1, C. Yang1 1 Department of Oral Surgery, Ninth People’s Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, and Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, Shanghai, China; 2Department of Craniomaxillofacial and Plastic Surgery, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
X. Liu, S. Wan, A. Abdelrehem, M. Chen, C. Yang: Benign temporomandibular joint tumours with extension to infratemporal fossa and skull base: condyle preserving approach. Int. J. Oral Maxillofac. Surg. 2019; xxx: xxx–xxx. ã 2019 Published by Elsevier Ltd on behalf of International Association of Oral and Maxillofacial Surgeons.
Abstract. This article introduces a modified surgical approach combining condylotomy with posterior disc attachment release for the resection of large nonmalignant masses located in the infratemporal fossa and involving the skull base. This retrospective study included 14 patients treated at Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University between January 2010 and December 2016. Clinical evaluations (visual analogue scale (VAS) for pain, maximum interincisal opening (MIO), and complications) and radiological findings (magnetic resonance imaging (MRI) and computed tomography (CT)) were collected pre- and postoperatively. All patients had satisfactory surgical exposure and complete resection of the neoplasms. During an average follow-up of 54.8 months, no clinical or radiographic signs of recurrence were reported. MIO increased from 28 mm preoperatively to 35.4 mm postoperatively (P < 0.001). The pain VAS score changed from 5.4 preoperatively to 0.7 postoperatively (P < 0.001). Neural function was normal for all patients. Postoperative MRI and CT scans showed a satisfactory disc position and condyle morphology, with no resorption. Threedimensional reconstruction of the postoperative CT scan also demonstrated healing of the skull base defects. The modified surgical approach combining condylotomy with posterior disc attachment release is suitable for the removal of large nonmalignant masses involving the infratemporal fossa and skull base.
0901-5027/000001+07
Key words: Infratemporal fossa tumor; Skull base; Condylotomy; Posterior disc attachment relsease; TMJ. Accepted for publication
ã 2019 Published by Elsevier Ltd on behalf of International Association of Oral and Maxillofacial Surgeons.
Please cite this article in press as: Liu X, et al. Benign temporomandibular joint tumours with extension to infratemporal fossa and skull base: condyle preserving approach, Int J Oral Maxillofac Surg (2020), https://doi.org/10.1016/j.ijom.2019.12.009
YIJOM-4343; No of Pages 7
2
Liu et al.
The management of large tumours originating in the temporomandibular joint (TMJ) that extend to the infratemporal fossa (ITF) or involve the skull base has always been a challenge1,2. Conventional approaches to expose tumours in the ITF that necessitate the resection of the condyle, coronoid process, or zygomatic arch are characterized by greater invasion, extra bleeding, and the loss of TMJ function4 . A previous study performed at Shanghai Jiao Tong University School of Medicine reported cases of diffuse giant cell tumour within the tendon sheath and pigmented villonodular synovitis (PVNS) of the TMJ with intracranial extension that were treated successfully by pre-auricular–transcondylar approach5. However, for those giant encapsulated neoplasms that are deeply located postero-medial to a normal condyle, with erosions of the glenoid fossa, obtaining full exposure of the lesion and achieving a complete resection of the
tumour via this approach with condylotomy alone remains difficult6. The aim of this study was to review a series of patients treated by modified condyle preserving approach for the excision of benign TMJ tumours with medial extension. Materials and methods
This retrospective study was approved by the Ethics Committee of Shanghai Jiao Tong University, School of Medicine (Shanghai, China), and implemented in accordance with all tenets of the Declaration of Helsinki for research. Patient information
The patients selected for this case series were treated in the Department of Oral Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine during the period January
2010 to December 2016. The inclusion criteria were as follows: (1) non-malignant tumours arising from the TMJ; (2) lesions mostly located deeply at the postero-medial aspect of the condyle; (3) the condyle and disc were normal; (4) the lesion was with or without an erosion of the skull base. All patients underwent complete clinical and imaging examinations (magnetic resonance imaging (MRI) and computed tomography (CT) of the TMJ) (Fig. 1). Surgical treatment—digital design
CT scan data (64-MDCT, General Electric Company, Massachusetts, USA, slice thickness 0.625 mm) were imported into ProPlan 1.3 software (Materialise NV, Leuven, Belgium) for preoperative three-dimensional reconstruction7. The tumours were analysed for size and shape. The location and the relationship with the surrounding important anatomical struc-
Fig. 1. Preoperative MRI and CT examinations of a 52-year-old male patient with synovial chondromatosis. (A) Oblique sagittal MRI revealed effusion and loose bodies in the upper compartment and resorption of the glenoid fossa; the appropriate disc position was observed; the condyle was not involved. (B) Coronal CT scan showed loose bodies distributed mostly in the medial region of the condyle and extending into the infratemporal fossa. A defect of the skull base was revealed; the appropriate condyle morphology was maintained. (C) A three-dimensional reconstruction of the CT scans demonstrated that the lesion was exclusively located in the infratemporal fossa and postero-medial to the condyle, and a defect of the skull base was revealed (white arrow).
Please cite this article in press as: Liu X, et al. Benign temporomandibular joint tumours with extension to infratemporal fossa and skull base: condyle preserving approach, Int J Oral Maxillofac Surg (2020), https://doi.org/10.1016/j.ijom.2019.12.009
YIJOM-4343; No of Pages 7
Benign TMJ tumours with skull base extension
3
Fig. 2. The surgical procedures. (A) The condyle neck, together with the lateral pterygoid muscle and the disc, was pulled forward and downward to fully expose the mass. (B) A diagram showing the division of the condylar neck with the lateral pterygoid muscle attachment preserved, and separation of the posterior attachment of the disc. After that, they were moved together in a forward and downward direction to expose the loose particles in the postero-medial part of the ITF, and the lesion (the blue arrow) could be removed completely (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article).
tures were also evaluated. The surgical approach and extent of tumour resection were then designed according to the measurements obtained1,8. Surgical procedure
All patients were operated on under general anaesthesia with nasal intubation by two surgeons (CY and MC) with more than 15 years of experience in TMJ surgeries. Through a pre-auricular incision with temporal extension, the TMJ was exposed5,6,9. The periosteum of the condylar neck was peeled off, and two titanium plates were bent to match the shape of the condylar neck. Guided by the digital
template, the condylar neck was divided with preservation of the lateral pterygoid muscle attachment5,6. After opening the upper joint compartment, the posterior attachment of the disc was separated to fully expose the tumour located in the postero-medial aspect of the ITF. (During this procedure, for better haemostasis, forceps were first used to clamp the attachment of the posterior part and then continuous suturing was done before dividing the tissues) (Fig. 2). The lesion was removed completely through the wide space just posterior to the condyle. If the lesion invaded the articular eminence, then the eminence was excised. In the case of glenoid fossa involvement, the region of perforation was cleared carefully to
avoid dura damage. The involved synovium, capsule, and surrounding soft tissues were excised as well. A temporal fascial flap was raised and transferred and placed between the condyle and fossa. Finally, the condyle was restored and fixed with the prepared titanium plates; then the posterior attachment of the disc was sutured (Fig. 3). Postoperative evaluation
Patients were followed up at regular intervals with both clinical and radiological evaluations (MRI and CT). The functions of the TMJ were evaluated using a visual analogue scale for pain (VAS; score 0–10, with higher scores
Fig. 3. The surgical procedures. (A) Reduction and fixation of the condyle during surgery. (B) A diagram showing the reduction and fixation with titanium plates of the condyle and repositioning of the disc with suture of the posterior attachment.
Please cite this article in press as: Liu X, et al. Benign temporomandibular joint tumours with extension to infratemporal fossa and skull base: condyle preserving approach, Int J Oral Maxillofac Surg (2020), https://doi.org/10.1016/j.ijom.2019.12.009
Sex
Age (years)
Diagnosis
Symptoms
Location
Preoperative VAS
1
F
52
SC
Clicking, pre-auricular pain, jaw deviation, open bite
2
F
24
VM
Joint sounds, preauricular pain, opening limitation, jaw deviation
3
M
56
SC
4
F
47
PVNS
Joint sounds, preauricular pain, jaw deviation Clicking, pre-auricular pain, jaw deviation
5
M
73
SC
Clicking, pre-auricular pain, swelling, jaw deviation
6
F
34
PVNS
Clicking, pre-auricular pain, pogonion deviation
7
M
45
SC
Joint sounds
8
M
32
SC
Clicking, pre-auricular pain, opening limitation
9
M
44
SC
Clicking, pre-auricular pain, jaw deviation, open bite
10
F
67
SC
Joint sounds, preauricular pain
Antero-medial and postero-medial of upper articular compartment (30 53 22 mm) Postero-medial of upper articular compartment, the mass wrapped around the condyle but without condylar destruction (37 49 29 mm) Postero-medial of upper articular compartment (35 39 25 mm) Posterior of superior articular compartment, the mass involved soft tissue of medial capsule and temporal bone (25 12 8 mm) Antero-medial and Postero-medial of upper articular compartment (49 35 45 mm) Posterior of superior articular compartment, the mass involved soft tissue of medial capsule and temporal bone (45 35 29 mm) Postero-medial of upper articular compartment (35 39 25 mm) Postero-medial of upper articular compartment (47 30 20 mm) Antero-medial and Postero-medial of upper articular compartment (49 35 45 mm) Postero-medial of upper articular compartment (35 53 23 mm)
Postoperative
7
MIO (mm) 35
Perforation (mm2) 28
7
10
8
VAS 1
MIO (mm) 40
Perforation (mm2) 7
Complications
22
1
32
–
Weak function of forehead lines (disappeared 6 months later)
56
30
–
0
34
–
–
60
6
28
26
2
32
–
–
96
3
30
9
0
35
–
–
72
6
26
–
0
34
–
–
59
0
34
22
0
42
–
–
96
8
12
19
1
32
–
–
48
6
28
–
2
32
–
–
40
7
30
26
3
34
12
Weak function of forehead lines (disappeared 6 months later)
42
–
Follow-up (months) 47
Liu et al.
Patient
YIJOM-4343; No of Pages 7
4
Please cite this article in press as: Liu X, et al. Benign temporomandibular joint tumours with extension to infratemporal fossa and skull base: condyle preserving approach, Int J Oral Maxillofac Surg (2020), https://doi.org/10.1016/j.ijom.2019.12.009
Table 1. General information of the patients.
YIJOM-4343; No of Pages 7
Joint sounds SC M 14
59
Clicking, pre-auricular pain, jaw deviation SC M 13
49
SC 52 M 12
F, female; M, male; MIO, maximum inter-incisal opening; PVNS, pigmented villonodular synovitis; SC, synovial chondromatosis; VAS, visual analogue scale (0–10, with higher scores indicating more severe pain); VM, venous malformation.
– 39 34 0
–
0
9 32 6
22
0
35
–
37
36
39 – 7 33 28 7
19
0
– 35 F 11
28
SC
Joint sounds, preauricular pain, jaw deviation Clicking, pre-auricular pain, jaw deviation
Postero-medial of upper articular compartment (47 32 25 mm) Postero-medial of upper articular compartment (23 30 20 mm) Antero-medial and postero-medial of upper articular compartment (45 36 33 mm) Postero-medial of upper articular compartment (35 49 31 mm)
5
–
0
42
–
39
Benign TMJ tumours with skull base extension indicating more severe pain), maximum inter-incisal opening (MIO), and occlusal stability. The recurrence rate and TMJ structure were evaluated by CT and MRI. Statistical analysis
The statistical analysis was performed using IBM SPSS Statistics version 21.0 (IBM Corp., Armonk, NY, USA). Data including descriptive statistics and categorical variables were obtained in the current study. The parametric paired t-test was used for continuous variables, while the x2 test was used for categorical variables. A probability value of less than 0.05 (P < 0.05) was considered as statistically significant. Results
Fourteen patients were included in this retrospective study (Table 1). There were six female patients and eight male patients, with an average age of 47.3 years (range 24–73 years). The left side was affected in four patients, while the right joint was involved in 10. Nine patients presented with deviation of the lower jaw upon mouth opening (deviation towards the normal unaffected side), and two of these nine patients also had an anterior open bite. In addition, one patient was observed to have chin deviation towards the affected side. Patients experienced TMJ clicking or joint sounds, and complained of pre-auricular pain on the ipsilateral side. There was no hearing loss or facial nerve palsy. According to the preoperative MRI and CT scans, the lesion originated from the upper compartment of the TMJ in 13 cases. The medial joint space was obviously enlarged with an extension into the ITF (mainly postero-medial to the condyle). The ipsilateral glenoid fossa and skull base were thinned out or perforated. The average perforation area was 21.4 mm2(range 9–28 mm2), less than 50% of the joint surface. Meanwhile, no condylar resorption or destruction were revealed. In a case with venous malformation, the mass wrapped around the condyle postero-medially without condylar resorption or deformation, and the skull base perforation was 22 mm2. In all cases, all lesions were fully exposed and completely resected using the modified surgical approach combining condylotomy and posterior disc attachment release. There was no need for blood transfusion during surgery. Pathological examination confirmed that 11 patients had synovial chondromatosis, two had
5
PVNS, and one had a venous malformation. During an average follow-up period of 54.8 months (range 36–96 months), no clinical or radiographic signs of recurrence were found. Compared with the preoperative average MIO of 28 mm (range 10–35 mm), the postoperative average MIO was increased to 35.4 mm (range 33–42 mm) (P < 0.001). The mean VAS score improved from 5.4 preoperatively to 0.7 postoperatively (P < 0.001). Only two patients showed weak eyebrow lifting, which had recovered 6 months later. There were no secondary dental or maxillofacial deformities. The postoperative MRI and CT scans showed a stable disc position and normal condyle morphology with no resorption (Fig. 4). Healing of the skull base perforation was demonstrated in nine cases with an average size of 17.6 mm2, evidenced by the matched fitting of CT scans. Discussion
Tumour and tumour-like lesions of the TMJ, such as synovial chondromatosis, PVNS, and vascular malformations, may extend into the ITF, skull base, and ear canal. Considering the fundamental characteristics of such tumours, including the deep location, indistinct boundaries, and abundant surrounding vessels/nerves, how to obtain a clear and less invasive surgical field has long been a great challenge to most surgeons1,10. Conventional approaches entail resection of the condyle, coronoid process, or zygomatic arch, resulting in more invasion, extra bleeding, and a loss of TMJ function4. Accordingly, there are also higher risks of postoperative complications including TMJ morphological and functional damage, secondary maxillofacial deformity and dysfunction, and a larger scar. In a previous study, Yang et al.6 reported a case of basal cell adenoma in the deep lobe of the parotid gland extending deeply to the condylar neck. The patient was successfully operated on through the pre-auricular–transcondylar approach. Later, the technique was modified by temporarily pushing the osteotomized condyle downward in a counterclockwise direction to expose the tumour located in the ITF5. However, condylotomy alone can only achieve a slight down-movement of the condyle, and the surgical field is only adequate to remove small lesions. In the current study, preoperative MRI showed that the tumour did not interfere with the TMJ disc, and there was no condylar resorption or destruction on CT
Please cite this article in press as: Liu X, et al. Benign temporomandibular joint tumours with extension to infratemporal fossa and skull base: condyle preserving approach, Int J Oral Maxillofac Surg (2020), https://doi.org/10.1016/j.ijom.2019.12.009
YIJOM-4343; No of Pages 7
6
Liu et al.
Fig. 4. Postoperative MRI and CT examinations. (A) Oblique sagittal MRI revealed the appropriate disc position. (B) Coronal CT scan showed the appropriate condyle morphology and healing of the skull base perforation. (C) A three-dimensional reconstruction of the CT demonstrated the full resection of the neoplasms, appropriate condyle morphology, and healing of the skull base perforation (white arrow).
scans as well. A three-dimensional reconstruction based on CT scans was conducted preoperatively to measure the parameters of the neoplasm including its size, location, and relationship with the adjacent anatomical structures7,8. The mass was found to have an average size of 36.7 27.3 22.3 mm, occupying the superior compartment, with involvement of the postero-medial capsule, articular fossa, and skull. Meanwhile, the lesion could not be adequately exposed or fully removed by condylotomy alone. So, it was decided to remove the lesion via a modified surgical approach that combined condylotomy with posterior disc attachment release. According to Iizuka et al.11, a long-term freely detached condyle might reveal necrosis or resorption. Moreover, the resorption rate of the condyle decreased to 6.7% only when the condyle was fixed back while keeping the lateral pterygoid attachment. So, in the technique presented here, the attachment of the lateral pterygoid muscle to the condyle was preserved in order to maintain the blood supply to the
condyle as well as to achieve a well-balanced forward and lateral movement of the mandible12. In addition, apart from the preauricular–transcondylar approach with temporary condylotomy, a transient posterior disc attachment release was applied. Together with the released disc, the osteotomized condyle attached to the lateral pterygoid muscle can move further forward and downward, with an increase of at least 2 cm. This approach resulted in sufficient space to fully expose the posteromedial part of the ITF and allowed complete removal of the giant tumour to be achieved, as well as repair of the corresponding skull base. For release of the posterior disc attachment, attention should be paid to haemostasis at the incision line and subsequent dissection13. An additional medial capsule incision could be considered to further expose the medial condyle aspect. As is well known, the articular disc is a good interosseous location to adapt the joint surface and joint fossa. As a shock absorber, the disc provides the flexibility and diversity of TMJ
movement. Meanwhile, it also contributes to the function of nutrition, lubrication, and sensation. Studies have reported that long-term disc displacement might cause condylar resorption or adhesion to the articular fossa14,15. Therefore, following resection of the lesion, the articular disc was sutured back with the fixed condyle to preserve the function and form of the TMJ. Three years after the surgery, the TMJ function was normal, with an average MIO of 35.4 mm, and no secondary dental or maxillofacial deformity occurred during this time. MRI showed that the articular disc capped on the top of the condyle had a good shape and moved together with the condyle in both opening and closing positions. CT demonstrated that the condylar head presented a good morphology with no resorption. As the perforation of the skull base was not bigger than the condylar head, the remainder of the glenoid fossa was strong enough to support the condyle. A temporal fascial fat flap pedicled on the middle temporal vessels was used to cover the cranial bone defect5. According to Jiang
Please cite this article in press as: Liu X, et al. Benign temporomandibular joint tumours with extension to infratemporal fossa and skull base: condyle preserving approach, Int J Oral Maxillofac Surg (2020), https://doi.org/10.1016/j.ijom.2019.12.009
YIJOM-4343; No of Pages 7
Benign TMJ tumours with skull base extension et al.13, the fat flap can be padded in the skull base when the perforation area is less than 50%. Meanwhile, as an interposition, a soft tissue flap can also prevent the condyle or articular disc from adhering to the exposed bone surface16. During surgery, other important structures should be considered: the cartilage surface should be protected while exposing the condyle; an extra excision of the articular eminence could be performed for removal of a mass that has intruded into the eminence; the dura should be protected while removing lesions involving the skull base; attention should be paid to the protection of the ear canal, especially the middle ear structures, when removing posterior lesions of the condyle. However, there are some limitations to this surgical method. First, the tumour should be a non-malignant lesion with a complete capsule. If the capsule is incomplete or the lesion shows a malignant character, an extended resection should be performed. The nature of the tumour should be judged by combining the preoperative imaging, endoscopic biopsy, and an intraoperative frozen biopsy. Second, for large tumours that cannot be removed even through the temporary condylotomy combined with posterior disc attachment release, other approaches should be advocated. In conclusion, the modified surgical approach combining condylotomy and posterior disc attachment release is suitable for the removal of large non-malignant masses involving the ITF and skull base. As well as exposing and fully removing the tumour, this technique also preserves the structure and function of the TMJ effectively. Funding
This study was supported by the Program of Doctor Innovation Fund of Shanghai Jiao Tong University School of Medicine (BXJ201930); the Program of National Natural Science Foundation of China (81870785); the Program of Pre-research (ky2018190174, ky2018190175) and Shanghai Summit and Plateau Disciplines. The funding sources had no role in the study design, collection, analysis, and interpretation of the data, or in the writing of the report.
Competing interests
The authors have stated explicitly that there are no conflicts of interest in connection with this article. Ethical approval
This retrospective study was designed in accordance with all tenets of the Declaration of Helsinki for research. The protocol was approved by the Ethics Committee of Shanghai Jiao Tong University, School of Medicine (Shanghai, China). Patient consent
All participants were informed of the research procedure and signed the participation consent agreement. References 1. Ye ZX, Yang C, Chen MJ, Huang D, Abdelrehem A. Digital resection and reconstruction of TMJ synovial chondrosarcoma involving the skull base: report of a case. Int J Clin Exp Med 2015;8:11589–93. 2. Merrill RG, Yih WY, Shamloo J. Synovial chondrosarcoma of the temporomandibular joint: a case report. J Oral Maxillofac Surg 1997;55:1312–6. 4. Mansour OI, Carrau RL, Snyderman CH, Kassam AB. Preauricular infratemporal fossa surgical approach: modifications of the technique and surgical indications. Skull Base 2004;14:143–51. discussion 151. 5. Chen Y, Cai XY, Yang C, Chen MJ, Qiu YT, Zhuo Z. Pigmented villonodular synovitis of the temporomandibular joint with intracranial extension. J Craniofac Surg 2015;26: e115–8. 6. Yang XJ, Yang C, Chen MJ, Zhang XH, Qiu YT, He DM, Wang LZ. Preauricular transcondylar approach for basal cell adenoma of parotid coexist with ganglion cyst of the ipsilateral temporomandibular joint. J Craniofac Surg 2011;22:e23–6. 7. Bai G, He D, Yang C, Lu C, Huang D, Chen M, Yuan J. Effect of digital template in the assistant of a giant condylar osteochondroma resection. J Craniofac Surg 2014;25:e301–4. 8. Huang D, He DM, Yang C, Chen MJ, Zhou Q, Dong MJ. Computer-assisted local resection for exostosis osteochondroma of the mandibular condyle. J Craniofac Surg 2013;24:e446–9. 9. Bai G, Yang C, Qiu Y, Chen M. Open surgery assisted with arthroscopy to treat synovial
7
chondromatosis of the temporomandibular joint. Int J Oral Maxillofac Surg 2017;46:208–13. 10. Tiwari R, Quak J, Egeler S, Smeele L, Waal IV, Valk OV, Leemans R. Tumors of the infratemporal fossa. Skull Base Surg 2000;10:1–9. 11. Iizuka T, Lindqvist C, Hallikainen D, Mikkonen P, Paukku P. Severe bone resorption and osteoarthrosis after miniplate fixation of high condylar fractures. A clinical and radiologic study of thirteen patients. Oral Surg Oral Med Oral Pathol 1991;72:400–7. 12. Chen M, Yang C, He D, Zhang S, Jiang B. Soft tissue reduction during open treatment of intracapsular condylar fracture of the temporomandibular joint: our institution’s experience. J Oral Maxillofac Surg 2010;68:2189–95. 13. Jiang B, Yang C, Chen MJ, Cai XY. Synovial chondromatosis of the temporomandibular joint with articular eminence extension. J Craniofac Surg 2012;23:716–8. 14. Zhang Y, He DM. Clinical investigation of early post-traumatic temporomandibular joint ankylosis and the role of repositioning discs in treatment. Int J Oral Maxillofac Surg 2006;35:1096–101. 15. Chuong R, Piper MA. Open reduction of condylar fractions of the mandible in conjunction with repair of discal injury: a preliminary report. J Oral Maxillofac Surg 1988;46:257–63. 16. Chen M, Yang C, Qiu Y, He D, Huang D, Wei W. Superior half of the sternoclavicular joint pedicled with the sternocleidomastoid muscle for reconstruction of the temporomandibular joint: a preliminary study with a simplified technique and expanded indications. Int J Oral Maxillofac Surg 2015;44:685–91.
Address: Chi Yang Department of Oral Surgery Ninth People’s Hospital College of Stomatology Shanghai Jiao Tong University School of Medicine and Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology No. 639 Zhi Zao Ju Rd 200011 Shanghai China E-mail: [email protected]
Please cite this article in press as: Liu X, et al. Benign temporomandibular joint tumours with extension to infratemporal fossa and skull base: condyle preserving approach, Int J Oral Maxillofac Surg (2020), https://doi.org/10.1016/j.ijom.2019.12.009
Int. J. Oral Maxillofac. Surg. 2019; xxx: xxx–xxx https://doi.org/10.1016/j.ijom.2019.12.009, available online at https://www.sciencedirect.com
Clinical Paper Clinical Pathology
Benign temporomandibular joint tumours with extension to infratemporal fossa and skull base: condyle preserving approach
X. Liu1, S. Wan1, A. Abdelrehem2, M. Chen1, C. Yang1 1 Department of Oral Surgery, Ninth People’s Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, and Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, Shanghai, China; 2Department of Craniomaxillofacial and Plastic Surgery, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
X. Liu, S. Wan, A. Abdelrehem, M. Chen, C. Yang: Benign temporomandibular joint tumours with extension to infratemporal fossa and skull base: condyle preserving approach. Int. J. Oral Maxillofac. Surg. 2019; xxx: xxx–xxx. ã 2019 Published by Elsevier Ltd on behalf of International Association of Oral and Maxillofacial Surgeons.
Abstract. This article introduces a modified surgical approach combining condylotomy with posterior disc attachment release for the resection of large nonmalignant masses located in the infratemporal fossa and involving the skull base. This retrospective study included 14 patients treated at Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University between January 2010 and December 2016. Clinical evaluations (visual analogue scale (VAS) for pain, maximum interincisal opening (MIO), and complications) and radiological findings (magnetic resonance imaging (MRI) and computed tomography (CT)) were collected pre- and postoperatively. All patients had satisfactory surgical exposure and complete resection of the neoplasms. During an average follow-up of 54.8 months, no clinical or radiographic signs of recurrence were reported. MIO increased from 28 mm preoperatively to 35.4 mm postoperatively (P < 0.001). The pain VAS score changed from 5.4 preoperatively to 0.7 postoperatively (P < 0.001). Neural function was normal for all patients. Postoperative MRI and CT scans showed a satisfactory disc position and condyle morphology, with no resorption. Threedimensional reconstruction of the postoperative CT scan also demonstrated healing of the skull base defects. The modified surgical approach combining condylotomy with posterior disc attachment release is suitable for the removal of large nonmalignant masses involving the infratemporal fossa and skull base.
0901-5027/000001+07
Key words: Infratemporal fossa tumor; Skull base; Condylotomy; Posterior disc attachment relsease; TMJ. Accepted for publication
ã 2019 Published by Elsevier Ltd on behalf of International Association of Oral and Maxillofacial Surgeons.
Please cite this article in press as: Liu X, et al. Benign temporomandibular joint tumours with extension to infratemporal fossa and skull base: condyle preserving approach, Int J Oral Maxillofac Surg (2020), https://doi.org/10.1016/j.ijom.2019.12.009
YIJOM-4343; No of Pages 7
2
Liu et al.
The management of large tumours originating in the temporomandibular joint (TMJ) that extend to the infratemporal fossa (ITF) or involve the skull base has always been a challenge1,2. Conventional approaches to expose tumours in the ITF that necessitate the resection of the condyle, coronoid process, or zygomatic arch are characterized by greater invasion, extra bleeding, and the loss of TMJ function4 . A previous study performed at Shanghai Jiao Tong University School of Medicine reported cases of diffuse giant cell tumour within the tendon sheath and pigmented villonodular synovitis (PVNS) of the TMJ with intracranial extension that were treated successfully by pre-auricular–transcondylar approach5. However, for those giant encapsulated neoplasms that are deeply located postero-medial to a normal condyle, with erosions of the glenoid fossa, obtaining full exposure of the lesion and achieving a complete resection of the
tumour via this approach with condylotomy alone remains difficult6. The aim of this study was to review a series of patients treated by modified condyle preserving approach for the excision of benign TMJ tumours with medial extension. Materials and methods
This retrospective study was approved by the Ethics Committee of Shanghai Jiao Tong University, School of Medicine (Shanghai, China), and implemented in accordance with all tenets of the Declaration of Helsinki for research. Patient information
The patients selected for this case series were treated in the Department of Oral Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine during the period January
2010 to December 2016. The inclusion criteria were as follows: (1) non-malignant tumours arising from the TMJ; (2) lesions mostly located deeply at the postero-medial aspect of the condyle; (3) the condyle and disc were normal; (4) the lesion was with or without an erosion of the skull base. All patients underwent complete clinical and imaging examinations (magnetic resonance imaging (MRI) and computed tomography (CT) of the TMJ) (Fig. 1). Surgical treatment—digital design
CT scan data (64-MDCT, General Electric Company, Massachusetts, USA, slice thickness 0.625 mm) were imported into ProPlan 1.3 software (Materialise NV, Leuven, Belgium) for preoperative three-dimensional reconstruction7. The tumours were analysed for size and shape. The location and the relationship with the surrounding important anatomical struc-
Fig. 1. Preoperative MRI and CT examinations of a 52-year-old male patient with synovial chondromatosis. (A) Oblique sagittal MRI revealed effusion and loose bodies in the upper compartment and resorption of the glenoid fossa; the appropriate disc position was observed; the condyle was not involved. (B) Coronal CT scan showed loose bodies distributed mostly in the medial region of the condyle and extending into the infratemporal fossa. A defect of the skull base was revealed; the appropriate condyle morphology was maintained. (C) A three-dimensional reconstruction of the CT scans demonstrated that the lesion was exclusively located in the infratemporal fossa and postero-medial to the condyle, and a defect of the skull base was revealed (white arrow).
Please cite this article in press as: Liu X, et al. Benign temporomandibular joint tumours with extension to infratemporal fossa and skull base: condyle preserving approach, Int J Oral Maxillofac Surg (2020), https://doi.org/10.1016/j.ijom.2019.12.009
YIJOM-4343; No of Pages 7
Benign TMJ tumours with skull base extension
3
Fig. 2. The surgical procedures. (A) The condyle neck, together with the lateral pterygoid muscle and the disc, was pulled forward and downward to fully expose the mass. (B) A diagram showing the division of the condylar neck with the lateral pterygoid muscle attachment preserved, and separation of the posterior attachment of the disc. After that, they were moved together in a forward and downward direction to expose the loose particles in the postero-medial part of the ITF, and the lesion (the blue arrow) could be removed completely (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article).
tures were also evaluated. The surgical approach and extent of tumour resection were then designed according to the measurements obtained1,8. Surgical procedure
All patients were operated on under general anaesthesia with nasal intubation by two surgeons (CY and MC) with more than 15 years of experience in TMJ surgeries. Through a pre-auricular incision with temporal extension, the TMJ was exposed5,6,9. The periosteum of the condylar neck was peeled off, and two titanium plates were bent to match the shape of the condylar neck. Guided by the digital
template, the condylar neck was divided with preservation of the lateral pterygoid muscle attachment5,6. After opening the upper joint compartment, the posterior attachment of the disc was separated to fully expose the tumour located in the postero-medial aspect of the ITF. (During this procedure, for better haemostasis, forceps were first used to clamp the attachment of the posterior part and then continuous suturing was done before dividing the tissues) (Fig. 2). The lesion was removed completely through the wide space just posterior to the condyle. If the lesion invaded the articular eminence, then the eminence was excised. In the case of glenoid fossa involvement, the region of perforation was cleared carefully to
avoid dura damage. The involved synovium, capsule, and surrounding soft tissues were excised as well. A temporal fascial flap was raised and transferred and placed between the condyle and fossa. Finally, the condyle was restored and fixed with the prepared titanium plates; then the posterior attachment of the disc was sutured (Fig. 3). Postoperative evaluation
Patients were followed up at regular intervals with both clinical and radiological evaluations (MRI and CT). The functions of the TMJ were evaluated using a visual analogue scale for pain (VAS; score 0–10, with higher scores
Fig. 3. The surgical procedures. (A) Reduction and fixation of the condyle during surgery. (B) A diagram showing the reduction and fixation with titanium plates of the condyle and repositioning of the disc with suture of the posterior attachment.
Please cite this article in press as: Liu X, et al. Benign temporomandibular joint tumours with extension to infratemporal fossa and skull base: condyle preserving approach, Int J Oral Maxillofac Surg (2020), https://doi.org/10.1016/j.ijom.2019.12.009
Sex
Age (years)
Diagnosis
Symptoms
Location
Preoperative VAS
1
F
52
SC
Clicking, pre-auricular pain, jaw deviation, open bite
2
F
24
VM
Joint sounds, preauricular pain, opening limitation, jaw deviation
3
M
56
SC
4
F
47
PVNS
Joint sounds, preauricular pain, jaw deviation Clicking, pre-auricular pain, jaw deviation
5
M
73
SC
Clicking, pre-auricular pain, swelling, jaw deviation
6
F
34
PVNS
Clicking, pre-auricular pain, pogonion deviation
7
M
45
SC
Joint sounds
8
M
32
SC
Clicking, pre-auricular pain, opening limitation
9
M
44
SC
Clicking, pre-auricular pain, jaw deviation, open bite
10
F
67
SC
Joint sounds, preauricular pain
Antero-medial and postero-medial of upper articular compartment (30 53 22 mm) Postero-medial of upper articular compartment, the mass wrapped around the condyle but without condylar destruction (37 49 29 mm) Postero-medial of upper articular compartment (35 39 25 mm) Posterior of superior articular compartment, the mass involved soft tissue of medial capsule and temporal bone (25 12 8 mm) Antero-medial and Postero-medial of upper articular compartment (49 35 45 mm) Posterior of superior articular compartment, the mass involved soft tissue of medial capsule and temporal bone (45 35 29 mm) Postero-medial of upper articular compartment (35 39 25 mm) Postero-medial of upper articular compartment (47 30 20 mm) Antero-medial and Postero-medial of upper articular compartment (49 35 45 mm) Postero-medial of upper articular compartment (35 53 23 mm)
Postoperative
7
MIO (mm) 35
Perforation (mm2) 28
7
10
8
VAS 1
MIO (mm) 40
Perforation (mm2) 7
Complications
22
1
32
–
Weak function of forehead lines (disappeared 6 months later)
56
30
–
0
34
–
–
60
6
28
26
2
32
–
–
96
3
30
9
0
35
–
–
72
6
26
–
0
34
–
–
59
0
34
22
0
42
–
–
96
8
12
19
1
32
–
–
48
6
28
–
2
32
–
–
40
7
30
26
3
34
12
Weak function of forehead lines (disappeared 6 months later)
42
–
Follow-up (months) 47
Liu et al.
Patient
YIJOM-4343; No of Pages 7
4
Please cite this article in press as: Liu X, et al. Benign temporomandibular joint tumours with extension to infratemporal fossa and skull base: condyle preserving approach, Int J Oral Maxillofac Surg (2020), https://doi.org/10.1016/j.ijom.2019.12.009
Table 1. General information of the patients.
YIJOM-4343; No of Pages 7
Joint sounds SC M 14
59
Clicking, pre-auricular pain, jaw deviation SC M 13
49
SC 52 M 12
F, female; M, male; MIO, maximum inter-incisal opening; PVNS, pigmented villonodular synovitis; SC, synovial chondromatosis; VAS, visual analogue scale (0–10, with higher scores indicating more severe pain); VM, venous malformation.
– 39 34 0
–
0
9 32 6
22
0
35
–
37
36
39 – 7 33 28 7
19
0
– 35 F 11
28
SC
Joint sounds, preauricular pain, jaw deviation Clicking, pre-auricular pain, jaw deviation
Postero-medial of upper articular compartment (47 32 25 mm) Postero-medial of upper articular compartment (23 30 20 mm) Antero-medial and postero-medial of upper articular compartment (45 36 33 mm) Postero-medial of upper articular compartment (35 49 31 mm)
5
–
0
42
–
39
Benign TMJ tumours with skull base extension indicating more severe pain), maximum inter-incisal opening (MIO), and occlusal stability. The recurrence rate and TMJ structure were evaluated by CT and MRI. Statistical analysis
The statistical analysis was performed using IBM SPSS Statistics version 21.0 (IBM Corp., Armonk, NY, USA). Data including descriptive statistics and categorical variables were obtained in the current study. The parametric paired t-test was used for continuous variables, while the x2 test was used for categorical variables. A probability value of less than 0.05 (P < 0.05) was considered as statistically significant. Results
Fourteen patients were included in this retrospective study (Table 1). There were six female patients and eight male patients, with an average age of 47.3 years (range 24–73 years). The left side was affected in four patients, while the right joint was involved in 10. Nine patients presented with deviation of the lower jaw upon mouth opening (deviation towards the normal unaffected side), and two of these nine patients also had an anterior open bite. In addition, one patient was observed to have chin deviation towards the affected side. Patients experienced TMJ clicking or joint sounds, and complained of pre-auricular pain on the ipsilateral side. There was no hearing loss or facial nerve palsy. According to the preoperative MRI and CT scans, the lesion originated from the upper compartment of the TMJ in 13 cases. The medial joint space was obviously enlarged with an extension into the ITF (mainly postero-medial to the condyle). The ipsilateral glenoid fossa and skull base were thinned out or perforated. The average perforation area was 21.4 mm2(range 9–28 mm2), less than 50% of the joint surface. Meanwhile, no condylar resorption or destruction were revealed. In a case with venous malformation, the mass wrapped around the condyle postero-medially without condylar resorption or deformation, and the skull base perforation was 22 mm2. In all cases, all lesions were fully exposed and completely resected using the modified surgical approach combining condylotomy and posterior disc attachment release. There was no need for blood transfusion during surgery. Pathological examination confirmed that 11 patients had synovial chondromatosis, two had
5
PVNS, and one had a venous malformation. During an average follow-up period of 54.8 months (range 36–96 months), no clinical or radiographic signs of recurrence were found. Compared with the preoperative average MIO of 28 mm (range 10–35 mm), the postoperative average MIO was increased to 35.4 mm (range 33–42 mm) (P < 0.001). The mean VAS score improved from 5.4 preoperatively to 0.7 postoperatively (P < 0.001). Only two patients showed weak eyebrow lifting, which had recovered 6 months later. There were no secondary dental or maxillofacial deformities. The postoperative MRI and CT scans showed a stable disc position and normal condyle morphology with no resorption (Fig. 4). Healing of the skull base perforation was demonstrated in nine cases with an average size of 17.6 mm2, evidenced by the matched fitting of CT scans. Discussion
Tumour and tumour-like lesions of the TMJ, such as synovial chondromatosis, PVNS, and vascular malformations, may extend into the ITF, skull base, and ear canal. Considering the fundamental characteristics of such tumours, including the deep location, indistinct boundaries, and abundant surrounding vessels/nerves, how to obtain a clear and less invasive surgical field has long been a great challenge to most surgeons1,10. Conventional approaches entail resection of the condyle, coronoid process, or zygomatic arch, resulting in more invasion, extra bleeding, and a loss of TMJ function4. Accordingly, there are also higher risks of postoperative complications including TMJ morphological and functional damage, secondary maxillofacial deformity and dysfunction, and a larger scar. In a previous study, Yang et al.6 reported a case of basal cell adenoma in the deep lobe of the parotid gland extending deeply to the condylar neck. The patient was successfully operated on through the pre-auricular–transcondylar approach. Later, the technique was modified by temporarily pushing the osteotomized condyle downward in a counterclockwise direction to expose the tumour located in the ITF5. However, condylotomy alone can only achieve a slight down-movement of the condyle, and the surgical field is only adequate to remove small lesions. In the current study, preoperative MRI showed that the tumour did not interfere with the TMJ disc, and there was no condylar resorption or destruction on CT
Please cite this article in press as: Liu X, et al. Benign temporomandibular joint tumours with extension to infratemporal fossa and skull base: condyle preserving approach, Int J Oral Maxillofac Surg (2020), https://doi.org/10.1016/j.ijom.2019.12.009
YIJOM-4343; No of Pages 7
6
Liu et al.
Fig. 4. Postoperative MRI and CT examinations. (A) Oblique sagittal MRI revealed the appropriate disc position. (B) Coronal CT scan showed the appropriate condyle morphology and healing of the skull base perforation. (C) A three-dimensional reconstruction of the CT demonstrated the full resection of the neoplasms, appropriate condyle morphology, and healing of the skull base perforation (white arrow).
scans as well. A three-dimensional reconstruction based on CT scans was conducted preoperatively to measure the parameters of the neoplasm including its size, location, and relationship with the adjacent anatomical structures7,8. The mass was found to have an average size of 36.7 27.3 22.3 mm, occupying the superior compartment, with involvement of the postero-medial capsule, articular fossa, and skull. Meanwhile, the lesion could not be adequately exposed or fully removed by condylotomy alone. So, it was decided to remove the lesion via a modified surgical approach that combined condylotomy with posterior disc attachment release. According to Iizuka et al.11, a long-term freely detached condyle might reveal necrosis or resorption. Moreover, the resorption rate of the condyle decreased to 6.7% only when the condyle was fixed back while keeping the lateral pterygoid attachment. So, in the technique presented here, the attachment of the lateral pterygoid muscle to the condyle was preserved in order to maintain the blood supply to the
condyle as well as to achieve a well-balanced forward and lateral movement of the mandible12. In addition, apart from the preauricular–transcondylar approach with temporary condylotomy, a transient posterior disc attachment release was applied. Together with the released disc, the osteotomized condyle attached to the lateral pterygoid muscle can move further forward and downward, with an increase of at least 2 cm. This approach resulted in sufficient space to fully expose the posteromedial part of the ITF and allowed complete removal of the giant tumour to be achieved, as well as repair of the corresponding skull base. For release of the posterior disc attachment, attention should be paid to haemostasis at the incision line and subsequent dissection13. An additional medial capsule incision could be considered to further expose the medial condyle aspect. As is well known, the articular disc is a good interosseous location to adapt the joint surface and joint fossa. As a shock absorber, the disc provides the flexibility and diversity of TMJ
movement. Meanwhile, it also contributes to the function of nutrition, lubrication, and sensation. Studies have reported that long-term disc displacement might cause condylar resorption or adhesion to the articular fossa14,15. Therefore, following resection of the lesion, the articular disc was sutured back with the fixed condyle to preserve the function and form of the TMJ. Three years after the surgery, the TMJ function was normal, with an average MIO of 35.4 mm, and no secondary dental or maxillofacial deformity occurred during this time. MRI showed that the articular disc capped on the top of the condyle had a good shape and moved together with the condyle in both opening and closing positions. CT demonstrated that the condylar head presented a good morphology with no resorption. As the perforation of the skull base was not bigger than the condylar head, the remainder of the glenoid fossa was strong enough to support the condyle. A temporal fascial fat flap pedicled on the middle temporal vessels was used to cover the cranial bone defect5. According to Jiang
Please cite this article in press as: Liu X, et al. Benign temporomandibular joint tumours with extension to infratemporal fossa and skull base: condyle preserving approach, Int J Oral Maxillofac Surg (2020), https://doi.org/10.1016/j.ijom.2019.12.009
YIJOM-4343; No of Pages 7
Benign TMJ tumours with skull base extension et al.13, the fat flap can be padded in the skull base when the perforation area is less than 50%. Meanwhile, as an interposition, a soft tissue flap can also prevent the condyle or articular disc from adhering to the exposed bone surface16. During surgery, other important structures should be considered: the cartilage surface should be protected while exposing the condyle; an extra excision of the articular eminence could be performed for removal of a mass that has intruded into the eminence; the dura should be protected while removing lesions involving the skull base; attention should be paid to the protection of the ear canal, especially the middle ear structures, when removing posterior lesions of the condyle. However, there are some limitations to this surgical method. First, the tumour should be a non-malignant lesion with a complete capsule. If the capsule is incomplete or the lesion shows a malignant character, an extended resection should be performed. The nature of the tumour should be judged by combining the preoperative imaging, endoscopic biopsy, and an intraoperative frozen biopsy. Second, for large tumours that cannot be removed even through the temporary condylotomy combined with posterior disc attachment release, other approaches should be advocated. In conclusion, the modified surgical approach combining condylotomy and posterior disc attachment release is suitable for the removal of large non-malignant masses involving the ITF and skull base. As well as exposing and fully removing the tumour, this technique also preserves the structure and function of the TMJ effectively. Funding
This study was supported by the Program of Doctor Innovation Fund of Shanghai Jiao Tong University School of Medicine (BXJ201930); the Program of National Natural Science Foundation of China (81870785); the Program of Pre-research (ky2018190174, ky2018190175) and Shanghai Summit and Plateau Disciplines. The funding sources had no role in the study design, collection, analysis, and interpretation of the data, or in the writing of the report.
Competing interests
The authors have stated explicitly that there are no conflicts of interest in connection with this article. Ethical approval
This retrospective study was designed in accordance with all tenets of the Declaration of Helsinki for research. The protocol was approved by the Ethics Committee of Shanghai Jiao Tong University, School of Medicine (Shanghai, China). Patient consent
All participants were informed of the research procedure and signed the participation consent agreement. References 1. Ye ZX, Yang C, Chen MJ, Huang D, Abdelrehem A. Digital resection and reconstruction of TMJ synovial chondrosarcoma involving the skull base: report of a case. Int J Clin Exp Med 2015;8:11589–93. 2. Merrill RG, Yih WY, Shamloo J. Synovial chondrosarcoma of the temporomandibular joint: a case report. J Oral Maxillofac Surg 1997;55:1312–6. 4. Mansour OI, Carrau RL, Snyderman CH, Kassam AB. Preauricular infratemporal fossa surgical approach: modifications of the technique and surgical indications. Skull Base 2004;14:143–51. discussion 151. 5. Chen Y, Cai XY, Yang C, Chen MJ, Qiu YT, Zhuo Z. Pigmented villonodular synovitis of the temporomandibular joint with intracranial extension. J Craniofac Surg 2015;26: e115–8. 6. Yang XJ, Yang C, Chen MJ, Zhang XH, Qiu YT, He DM, Wang LZ. Preauricular transcondylar approach for basal cell adenoma of parotid coexist with ganglion cyst of the ipsilateral temporomandibular joint. J Craniofac Surg 2011;22:e23–6. 7. Bai G, He D, Yang C, Lu C, Huang D, Chen M, Yuan J. Effect of digital template in the assistant of a giant condylar osteochondroma resection. J Craniofac Surg 2014;25:e301–4. 8. Huang D, He DM, Yang C, Chen MJ, Zhou Q, Dong MJ. Computer-assisted local resection for exostosis osteochondroma of the mandibular condyle. J Craniofac Surg 2013;24:e446–9. 9. Bai G, Yang C, Qiu Y, Chen M. Open surgery assisted with arthroscopy to treat synovial
7
chondromatosis of the temporomandibular joint. Int J Oral Maxillofac Surg 2017;46:208–13. 10. Tiwari R, Quak J, Egeler S, Smeele L, Waal IV, Valk OV, Leemans R. Tumors of the infratemporal fossa. Skull Base Surg 2000;10:1–9. 11. Iizuka T, Lindqvist C, Hallikainen D, Mikkonen P, Paukku P. Severe bone resorption and osteoarthrosis after miniplate fixation of high condylar fractures. A clinical and radiologic study of thirteen patients. Oral Surg Oral Med Oral Pathol 1991;72:400–7. 12. Chen M, Yang C, He D, Zhang S, Jiang B. Soft tissue reduction during open treatment of intracapsular condylar fracture of the temporomandibular joint: our institution’s experience. J Oral Maxillofac Surg 2010;68:2189–95. 13. Jiang B, Yang C, Chen MJ, Cai XY. Synovial chondromatosis of the temporomandibular joint with articular eminence extension. J Craniofac Surg 2012;23:716–8. 14. Zhang Y, He DM. Clinical investigation of early post-traumatic temporomandibular joint ankylosis and the role of repositioning discs in treatment. Int J Oral Maxillofac Surg 2006;35:1096–101. 15. Chuong R, Piper MA. Open reduction of condylar fractions of the mandible in conjunction with repair of discal injury: a preliminary report. J Oral Maxillofac Surg 1988;46:257–63. 16. Chen M, Yang C, Qiu Y, He D, Huang D, Wei W. Superior half of the sternoclavicular joint pedicled with the sternocleidomastoid muscle for reconstruction of the temporomandibular joint: a preliminary study with a simplified technique and expanded indications. Int J Oral Maxillofac Surg 2015;44:685–91.
Address: Chi Yang Department of Oral Surgery Ninth People’s Hospital College of Stomatology Shanghai Jiao Tong University School of Medicine and Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology No. 639 Zhi Zao Ju Rd 200011 Shanghai China E-mail: [email protected]
Please cite this article in press as: Liu X, et al. Benign temporomandibular joint tumours with extension to infratemporal fossa and skull base: condyle preserving approach, Int J Oral Maxillofac Surg (2020), https://doi.org/10.1016/j.ijom.2019.12.009